Illuminated clock

ABSTRACT

An illuminated clock specifically for use in a photographic darkroom or similar confines, where protection against certain light rays is of necessity, composed of a housing including an illuminated time dial provided with means to interchangeably mount light ray absorbing filters within the housing in front of the illuminated dial to screen out and dampen the radiation of optical wavelengths emanating from the illuminated dial.

United States Patent [72] Inventor William H. Loftis 359 Maxlow, HazelPark, Mich. 48030 1211 Appl. No. 779,134 [22] Filed Nov. 26, 1968 [45]Patented June 22, 1971 [54] ILLUMINATED CLOCK 1 Claim, 3 Drawing Figs.

[52] U.S. Cl 240/2.l, 240/20, 240/46.45, 240/46.59, 58/50 [51] Int. Cl..G04b 19/30, F21v 9/00 [50] Field ofSearch 240/l.3,2,21,643,112,20,413,4l.15,41.4,41.55, 46.45, 4659; 58/19, 50

[56] References Cited UNITED STATES PATENTS 58 1,330,916 2/1920 Slade240/46.59

Primary Examiner-Samuel S Matthews Assistant Examiner-Joseph F. Peters,Jr. Anomey1-lauke, Gifford and Patalidis ABSTRACT: An illuminated clockspecifically for use in a photographic darkroom or similar confines,where protection against certain light rays is of necessity, composed ofa housing including an illuminated time dial provided with means tointerchangeably mount light ray absorbing filters within the housing infront of the illuminated dial to screen out and dampen the radiation ofoptical wavelengths emanating from the illuminated dial.

PATENTEU JUN22 1971 FIG. I

FIGS

INVENTOR WILLIAM H. LOFTIS BY ad fit,

ILLUMINATED CLOCK BACKGROUND OF THE INVENTION 1. Field of The InventionThe present invention refers in general to illuminated clocks inconjunction with a safe-light feature, and more specifically to anilluminating device which can be safely used in a photographic darkroom,hospital room or the like when in emission of normal optical light raysfrom the illuminating device would prove to be harmful.

2. Description Of The Prior Art Illuminating devices embodying a clockdial are known in the art, the most common being clocks provided withdials and hands coated with a phosphate solution, which glow in thedark. Although these are sufficient for reading the time in a darkenedroom, they do not provide sufficient light for a person to move about ina darkened'room or to read, or perform any other activities without theaid of an additional light.

Likewise, electrically or battery operated dial clocks have beenprovided heretofore which are adapted to illuminate the clock dial andat the same time serve as a night light, T.V. light or the like,permitting the movement about of a person in an otherwise darkened room.Although these devices perform satisfactorily for the need for whichthey are designed, they are not adaptable for specific uses such as in aphotographic darkroom or in a room occupied by a person having a seriouseye infiiction where it is required to keep away any unrestrictedradiation of optical light rays in whatever form.

Electroluminescent cells have been proposed as night lights, bedsidelights or the like, and in conjunction with a clock dial as anilluminated clock. Although these cells emit a soft, glowing light, theyare likewise not adaptable for use in a photographic darkroom sincetheir radiation of optical wave lengths is still of such range as tocause a harmful effect on the photographic film to be developed.

SUMMARY or THE INVENTION By the novel features disclosed herein, thepresent invention provides a safe light for photographic darkrooms orthe like having light radiation within a range so as not to exposephotographic film, but sufficient to permit a person to move about inthe darkened room. This is accomplished by the provision of lightfilters placed in front of the light source, which may be in the form oflow power light bulbs, to provide a low level of illumination of a saferadiation length which will not effect exposure of the film.

A time indication means can preferably be combined with the above safetylight since time is of the essence in the film developing process toenable the darkroom operator to clearly read the time in the otherwisedarkened room. In this case, a transparent clock dial can be providedfor positioning in front of the light source between the light sourceand the light filter, the light filter being of such construction as tobe sufficiently transparent to permit easy reading of the lighted clockdial.

The novel structure is preferably embodied in a light-tight insulatedhousing which is provided with adjustable pivotal support means topermit adjusting of the device to a preferred position.

BRIEF DESCRIPTION OF THE DRAWINGS Additional novel features will becomeevident or specifically be pointed out in the following detaileddescription by reference to the appended drawings illustrating apreferred embodiment.

FIG. 1 is an assembly view of the present novel illuminating devicepartly in cross section to show the interior construction.

FIG. 2 is a transverse cross section of the device in FIG. Irepresenting a plan view of the illuminated clock dial.

FIG. 3 is a front view of the novel device in FIG. I showing a lightfilter mounted in place in front of the clock dial.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIG. l,'thepresent novel illuminating device may comprise a substantiallycylindrical housing 10 having closed end indicated at 12 and an openfront indicated at 14. Instead of being cylindrical, the housing 10 maybe square or rectangular as desired.

The housing 10 is pivoted on a pedestal 16 which in turn is pivotal on asupport bracket 18 by which the housing 10 is secured to any suitablesurface 20. By loosening and thereafter tightening of the respectivepivotal pins 22 and 24, the housing 10 may be adjusted to any desiredconvenient position.

The housing 10 encloses the present novel illuminating device and clockmechanism comprised of a motor 26, positioned in the rear of the housingand having an electrical connection by means of a conduit 28 extendingout of the housing to establish contact through a suitable plug (notshown) with any available source of electrical current, such as commonhousehold or plant current.

The motor 26 is suitably secured within the housing 10 by means of asupport bracket 30 and is adapted to drive a clock mechanism (not shown)commonly associated with the motor in order to rotate a conventionaltelescoping shaft assembly 32 extending from the motor 26 longitudinallythrough the center of the housing 10, towards the front thereof.

The ends of the shaft assembly 32 receive the usual hour hand 34 andminute hand 36 respectively for rational rotation by the shaft assembly32. The end of the shaft assembly 32 immediately adjacent to the rear ofthe hands is rotatively supported centrally within a transparent shield38 which is suitably fastened within the housing 10. The front surfaceof the transparent shield 38 is provided with numerals 40 as seen inFIG. 2 to provide a clock-face or dial 42. A second transparent shield44 is positioned in front of the hands and the dial 42 which is likewisesuitably secured within the housing 10 and which is without any markingsto provide a clear view of the dial 42. Thus, the hands 34 and 36 areenclosed within the transparent shields 38 and 44 which are preferablysealed into the housing 10 to prevent the entry of foreign matter intothe clock mechanism. The transparent shields may be made of naturalglass, artificial glass, such as plexiglass, or clear nonwarpingplastic, whichever material is found to be more suitable.

Situated behind the transparent shields 38 and 44 and in front of themotor 26 is an illuminating device 46 which comprises a reflector 48,mounted on the front extension 27 of the motor 26.

The reflector 48 has a central bracket portion 50 onto which are mounteda pair of lamp sockets 52 and 54 respectively located to both sides ofthe clock drive shaft assembly 32. The sockets 52 and 54 adapted to eachreceive a light bulb 56 of relatively low power (for instance 6 voltshas been found to be adequate) and are provided with terminals 58 and 60at the rear of the central bracket portion 50 to which are attachedelectrical wires 62 and 64 respectively, which are connected within themotor 26 to the source of electric current. The circuit for the bulbs iscompleted by branch wires 66 and 68, which are connected to an OFF-ONswitch 70 outside of the housing 10, to permit switching the light bulbs56 ON or OFF as desired.

A shield of insulating material 72 is preferably provided between thereflector 48 and motor 26, which is supported on the front extensionthereof, and through which the electric wires 62 and 64 extend.

The open front 14 of the housing 10 is provided with external threads 74adapted to receive a screw-on cap 76 which is laterally provided withcircumferentially spaced lips 78 (FIG. 3). The screw cap 76 is adaptedto secure and clamp a light filter 80 over the open front end of thehousing in front of the dial 42. Upon tightening of the screw cap 76,the light filter 80 is securely held in place by the lips 78 against thecircumferential edge 82 of the open end of the housing 10.

The light filter 80 is of suitable construction and characteristic so asto selectively absorb certain light rays emitted from the bulbs 56through the transparent shields 38 and 44 to allow only such rays topass as will not cause film exposure during the development process inthe darkroom, but is of such color and transparency as to permit a clearview of the lighted clock dial through the filter. Light filters of thistype are commercially available and due to the screw-on cap arrangementone filter may be easily exchanged for a filter of another type as mayrequired in any particular application.

Obviously, the lighting means shown herein as bulbs 56 may be replacedby other suitable lighting means, such as fluorescent lights or thelike, and no limitation is intended to be placed on the invention by theparticular light means shown.

In order to allow access to the inside of the housing for servicing themotor 26 and the electrical connections without having to disassemblethe unit, and for setting the hands 34 and 36, a door 84 may be providedat the rear of the housing, which is attached to the housing by hinges86 and normally closed by a pivotal hook 88.

Thus, the present invention provides an improved combination of safelight and illuminated clock for use in darkened rooms where it isrequired to filter out certain light rays emitted from the lightingmeans. This is accomplished by the provision of a filter disposedforward of the illuminated clock dial for protection against radiationof optical wave lengths which would be harmful, for instance, to a filmwhen the device is being used in a film-processing darkroom.

The device provides a low level of illumination ofa safe intensity whichwill not affect the film, at the same time providing a time indicationmeans for the development process.

The invention may be embodied in other forms without departing from thespirit and essential characteristic thereof. Therefore, the presentembodiment is to be considered in all respects as illustrative only andnot restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description.

lclaim:

1. An illuminated clock device for use in a photographic dark roomcomprising a lightproof housing open at one end, an electrical lightsource in said housing for emitting light rays, said light sourcemounted on a reflector shield, at least one shield of transparentmaterial disposed in said housing forwardly of said light source, aclock mechanism mounted behind said reflector shield and including ashaft extending through said reflector shield and through saidtransparent shield, a clock dial formed on said transparent shield andclock hands mounted to said shaft in front of said clock dial, filtermeans mounted to said housing in front of said clock dial for absorbingoptical wave lengths harmful to photographic film, said filter meansincluding screw threads formed on the exterior surface of said housing,a removable screw cap adapted to engage said screw threads, retainingmeans provided on said screw caps, and a light filter adapted to placedin said screw cap against the retaining means so that said filter isclamped between said retaining means and said open end of said housingupon tightening of said screw cap upon said hous-

1. An illuminated clock device for use in a photographic dark roomcomprising a lightproof housing open at one end, an electrical lightsource in said housing for emitting light rays, said light sourcemounted on a reflector shield, at least one shield of transparentmaterial disposed in said housing forwardly of said light source, aclock mechanism mounted behind said reflector shield and including ashaft extending through said reflector shield and through saidtransparent shield, a clock dial formed on said transparent shield andclock hands mounted to said shaft in front of said clock dial, filtermeans mounted to said housing in front of said clock dial for absorbingoptical wave lengths harmful to photographic film, said filter meansincluding screw threads formed on the exterior surface of said housing,a removable screw cap adapted to engage said screw threads, retainingmeans providEd on said screw caps, and a light filter adapted to placedin said screw cap against the retaining means so that said filter isclamped between said retaining means and said open end of said housingupon tightening of said screw cap upon said housing.